In this article, we propose a new registration algorithm and computing framework, the KEG tracker, for estimating a camera's position and orientation for a general class of mobile context-aware applications in Arc...
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In this article, we propose a new registration algorithm and computing framework, the KEG tracker, for estimating a camera's position and orientation for a general class of mobile context-aware applications in Architecture, Engineering, and Construction (AEC). By studying two classic natural marker-based registration algorithms, Homography-from-detection and Homography-from-tracking, and by overcoming their specific limitations of jitter and drift, our method applies two global constraints (geometric and appearance) to prevent tracking errors from propagating between consecutive frames. The proposed method is able to achieve an increase in both stability and accuracy, while being fast enough for real-time applications. Experiments on both synthesized and real-world test cases demonstrate that our method is superior to existing state-of-the-art registration algorithms. The article also explores several AEC applications of our method in context-aware computing and desktop-augmented reality.
Due to the decoding complexity of network coding, there have been concerns on adopting network coding in the practical P2P systems. To provide rapid decoding speed in practical network coding systems, various multi-th...
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Due to the decoding complexity of network coding, there have been concerns on adopting network coding in the practical P2P systems. To provide rapid decoding speed in practical network coding systems, various multi-threaded approaches which successfully exploit hardware supported TLP have been proposed. Among those parallel approaches, a dynamic partitioning method is known to be the best solution so far. However, the algorithm dynamically changes workload distribution and inherently contains some limits to utilize the SIMD instruction set which are designed to work on a fixed size of data. In this paper, we present a new data manipulation method to utilize SIMD instruction sets, which can be successfully integrated into the dynamic partitioning of thread-level workload distribution. With exploiting both SIMD and thread-level parallelism, we achieve the speed-up of 10.86 using eight running threads compared to the serial algorithm. (C) 2012 Elsevier Ltd. All rights reserved.
The objective of this study is to develop playability heuristics based on a lexical analysis of nouns and adjectives frequently used in online game reviews. Built on a previous lexical analysis of adjectives in online...
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The objective of this study is to develop playability heuristics based on a lexical analysis of nouns and adjectives frequently used in online game reviews. Built on a previous lexical analysis of adjectives in online game reviews, it is argued that nouns together with adjectives will likely provide more contextual information than adjectives alone, and therefore the patterns among these words can be used to develop playability heuristics. A revised lexical approach is adopted to analyze nouns and adjectives from 821,122 online reviews. Ninety seven factors emerge from this analysis. Based on the nouns and adjectives highly loaded on these factors, a new process is introduced and 90 playability heuristics are derived. This study significantly expands the current pool of playability heuristics that facilitate the computer game design process. The lexical method adopted in this study demonstrates its effectiveness in developing interface design guidelines based on a large number of online reviews on a system or product. It can be extended to other fields that are human-behavior centered.
An efficient parallel iterative method with parameters on distributed-memory multicomputer is investigated for solving the banded linear equations in this work. The parallel algorithm at each iterative step is execute...
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An efficient parallel iterative method with parameters on distributed-memory multicomputer is investigated for solving the banded linear equations in this work. The parallel algorithm at each iterative step is executed using alternating direction by splitting the coefficient matrix and using parameters properly. Only it twice requires the communications of the algorithm between the adjacent processors, so this method has high parallel efficiency. Some convergence theorems for different coefficient matrices are given, such as a Hermite positive definite matrix or an M-matrix. Numerical experiments implemented on HP rx2600 cluster verify that our algorithm has the advantages over the multisplitting one of high efficiency and low memory space, which has a considerable advantage in CPU-times costs over the BSOR one. The efficiency for Example 1 is better than BSOR one significantly. As to Example 2, the acceleration rates and efficiency of our algorithm are better than the PEk inner iterative one.
This paper describes a head-neck-eye camera system that is capable of learning to saccade to 3-D targets in a self-organized fashion. The self-organized learning process is based on action perception cycles where the ...
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This paper describes a head-neck-eye camera system that is capable of learning to saccade to 3-D targets in a self-organized fashion. The self-organized learning process is based on action perception cycles where the camera system performs micro saccades about a given head-neck-eye camera position and learns to map these Micro saccades to changes in position of a 3-D target currently in view of the stereo camera. This motor babbling phase provides self-generated movement commands that activate correlated visual, spatial and Motor information that are used to learn ail internal coordinate transformation between vision and motor systems. The learned transform is used by resulting head-neck-eye camera system to accurately saccade to 3-D targets using many different combinations of head, neck, and eye positions. The interesting aspect of the learned transform is that it is robust to a wide variety of disturbances including reduced degrees of freedom of movement for the head, neck, one eye, or any combination of two of the three, movement of lead and neck as a function of eye movements, changes in the stereo camera separation distance and changes in focal lengths of the cameras. These disturbances were not encountered during motor babbling phase. This feature points to general nature of the learned transform in its ability to control autonomous systems with redundant degrees of freedom in a very robust and fault-tolerant fashion. (C) 2008 Elsevier Ltd. All rights reserved.
Fault prediction is an effective and important approach to improve the reliability and reduce the risk of accidents for complex electromechanical systems. In order to use the quantitative information and qualitative k...
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Fault prediction is an effective and important approach to improve the reliability and reduce the risk of accidents for complex electromechanical systems. In order to use the quantitative information and qualitative knowledge efficiently to predict the fault, a new model is proposed on the basis of belief rule base (BRB). Moreover, an evidential reasoning (ER) based optimal algorithm is developed to train the fault prediction model. The screw failure in computer numerical control (CNC) milling machine servo system is taken as an example and the fault prediction results show that the proposed method can predict the behavior of the system accurately with combining qualitative knowledge and some quantitative information.
Link adaptation techniques, where the modulation, coding rate, and/or other signal transmission parameters are dynamically adapted to the changing channel conditions, have recently emerged as powerful tools for increa...
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Link adaptation techniques, where the modulation, coding rate, and/or other signal transmission parameters are dynamically adapted to the changing channel conditions, have recently emerged as powerful tools for increasing the data rate and spectral efficiency of wireless data-centric networks. While there has been significant progress on understanding the theoretical aspects of time adaptation in LA protocols, new challenges surface when dynamic transmission techniques are employed in broadband wireless networks with multiple signaling dimensions. Those additional dimensions are mainly frequency, especially in multicarrier systems, and space in multiple-antenna systems, particularly multiarray multiple-input multiple-output communication systems. In this article we give an overview of the challenges and promises of link adaptation in future broadband wireless networks. We suggest guidelines to help in the design of robust, complexity/cost-effective algorithms for these future wireless networks.
The article presents a comparative study of three procedures applied for solving the inverse Stefan problem. The investigated problem consists of reconstruction of the unknown boundary condition on the basis of measur...
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The article presents a comparative study of three procedures applied for solving the inverse Stefan problem. The investigated problem consists of reconstruction of the unknown boundary condition on the basis of measurement data, and the procedures of solution differ in the way of minimizing the proper functional-in each approach considered, one of three artificial intelligence algorithms (Ant Colony Optimization, Artificial Bee Colony, and Harmony Search) is used. Methods applying the respective algorithms are compared with regard to their velocity and the precision of results.
This study analyses unsymmetrical voltage sag effects on the torque and speed deviation in induction motor (IM) adjustable speed drives. The following three general types of IM drives control are analysed: scalar cont...
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This study analyses unsymmetrical voltage sag effects on the torque and speed deviation in induction motor (IM) adjustable speed drives. The following three general types of IM drives control are analysed: scalar controlled (V/Hz), rotor-field oriented and direct-torque controlled. The analytical expressions for dc-link voltage variations incorporated into the corresponding drive models as well as formulas for assessment of current/torque deviation are derived depending on the applied control algorithm. The analytically predicted theoretical results for the IM drive performance deterioration as a result of voltage sags have been validated experimentally. Measurements of sag-caused current/torque ripple and mechanical vibrations have been used for additional verification of the obtained results.
In the paper, combinatorial issues of the factorization of linear ordinary differential operators are studied. It is proved that any finite distributive lattice is that of right divisors of some d'Alembert linear ...
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In the paper, combinatorial issues of the factorization of linear ordinary differential operators are studied. It is proved that any finite distributive lattice is that of right divisors of some d'Alembert linear ordinary differential operator with the coefficients belonging to the differential field C(x) of rational functions.
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